https://bioinformaticsonline.com/snippets/view/41164/bash-oneliner-to-extract-all-ids-from-a-multifasta-file? https://bioinformaticsonline.com/snippets/view/41164/bash-oneliner-to-extract-all-ids-from-a-multifasta-file Tue, 18 Feb 2020 08:06:09 -0600 https://bioinformaticsonline.com/snippets/view/41164/bash-oneliner-to-extract-all-ids-from-a-multifasta-file #List of ids - one per line in allIds.txt $ awk 'BEGIN{while((getline<"allIds.txt")>0)l[">"$1]=1}/^>/{f=!l[$1]}f' seq.fa # You can play with this f=!l[$1 ] if wanted to extract or not extract the ids]]> biogeek